Because Lake Travis is the( deepest lake in Tx )at a Max depth of 210 feet it will really take some water to fill up . Lake Travis is considered full ( AT maximum desired capacity ) when the lake's water level is at 681 feet above mean sea level . Above 681 feet flood control gates are opened under the direction of the US Army Corps Of Engineers . The historic high level on the lake was 710.4 feet on Dec 25, 1991 . Historic low was 614.2 feet on Aug 14, 1951 . The extreme drought of 2008 -2009 brought the lake to its lowest level at 626.09 feet above msl in Nov 2009. The second lowest level was 615.02 feet above msl on Nov 8, 1963 Due to the 2010 -13 Southern United States drought levels have gone as low as 618 feet , making it the 3rd lowest level ever . The LCRA makes reports of lake levels available on the internet . Surface area is 18,930 acres Water Volume 1,130,000acre .ft
Sam Rayburn Reservior is the largest lake Wholly located in Tx . surface area is 114,500 acres & water Volume 3,997,600 acres . ft .
Lake Houston has surface area of 11,854 acres Max depth 45 ft Water Volume 160, 000 acre . ft Water for City of Houston .
Lake Livingston has surface area of 83,000 acres Max depth 90 ft Average depth 20 ft Water Volume 1,750,000 acre ft . City of Houston owns two-thirds of the water rights of the lake with the other 1/3 remaining under control of the TRA
Lake Conroe has over 22,000 acres of surface water Max depth of 70 feet average depth is 20 ft .This lake also is an alternate water source for City of Houston .